字幕表 動画を再生する 英語字幕をプリント {♫Intro♫} In March 2020, a pair of scientists in North Dakota proposed putting the cloud on Mars. You know, “the cloud,” that nebulous computer… thing. That stores… stuff. But while it might sound like just a string of buzzwords, it's a legitimate idea -- one that could fundamentally change how we plan space missions. Because we use the cloud here on Earth for lots of things: file storage, computations, whatever. And probes won't need to do all that on their own if the cloud is already there for them. “The cloud” is really just a fancy way to say “someone else's computer”. “Putting the cloud on Mars” is therefore the fancy version of “putting a bunch of computers on Mars.” It wouldn't be out there for us to use, but rather our trusty space robots. See, it takes about half an hour to send a signal to Mars and back, and data transfer rates aren't great. It's just hard to send information-packed signals across such a big distance. So a Martian cloud would be out there mainly for missions taking place on and around Mars. The idea is that a company like SpaceX could send the computers there and set up the system, and then NASA or anyone else could rent time on the computers to make up the costs. It wouldn't be cheap to send all these computers to Mars, but here's the thing: We do that anyway, for every mission. They all need computers to work. And space is a pretty hostile place if you're a computer. Interplanetary space is full of computer-corrupting radiation, and Mars doesn't have a strong magnetic field that stops that radiation from reaching the ground. Then there's micrometeorites, cold, dust -- Mars just isn't a very pleasant place to be. All of this is why Martian probes are built with redundancy: They have multiple, heavily protected computers that can step in if one breaks. But doubling the number of computers and shielding them all adds weight. Every kilogram sent to Mars can cost between thousands and hundreds of thousands of dollars, depending on the mission. So probes end up with compromises -- lighter computers that aren't as powerful they could be. But if we already had a bunch of computers out there that probes could tap into, the probes could have access to more juice for less weight. As long as the probe's antenna -- and also its backup antenna -- don't break, that is. If it can't talk to us, it also can't talk to the cloud. Sure, there are still potential problems with getting those cloud computers to Mars. And it wouldn't be cheap. In that 2020 paper, published in the journal Acta Astronautica, the researchers calculated that it would cost around 1.5 billion dollars to send and set up a Martian cloud, with regular upkeep averaging out at something like a thousand additional dollars an hour. That's a lot to sink into something nobody really asked for -- at least as far as we can tell. Though they also figured the costs could be made up in about five years. So what would we actually do with a Martian cloud? Well, whatever we want. That's what we do with computers. It's only a matter of time before someone configures Curiosity to run Doom. Actually, though, some missions could use the cloud to store their data and transmit it back to Earth. A dedicated cloud system using technology that we're developing anyway might be able to send data back up to a hundred times faster than current probes do, letting rovers spend more time exploring and less time talking. With less memory needed onboard, engineers could use the weight savings to cut mission costs, or add instruments that would have been cut otherwise. Others could use the computers for, you know, computations: Calculating the safest way to land, say, if something goes wrong and there's no time to contact Earth. But the really fun possibilities open up with missions that would use a Martian cloud for coordination between multiple robots. Because there are a lot of mission proposals out there that don't just feature one or two probes, like we've been sending for decades. Why send two robots when you could send dozens? The more you have, the more ground they can cover. Humans would take forever to work out paths for each of those robots. But the cloud could run programs that kept the little bots from crashing into each other while also accounting for the Martian terrain, toeing the always-tricky line of finding interesting places that aren't so interesting they break a robot. A while back, we talked about one of these ideas: HOPTERs that jump around Mars instead of using wheels. But that's not the only proposed multi-bot mission. In 2004, a group looked specifically at three-robot teams that could help each other down cliffs. A network of those around Mars would let us get into all sorts of craters that are inaccessible right now. In 2007, another team imagined a whole swarm of sensors so small that they could be carried by the wind, like dust. A cloud of computers might take in data from this cloud of sensors better than anything else. So, in the end, do we need to put the cloud on Mars? Well, strictly speaking, of course not. We don't need to go to Mars at all! But we want to, and the cloud could theoretically make things more flexible, and enable new modes of exploration, so hey. Maybe it's worth a try. Thanks for watching this episode of SciShow Space. Our patrons help us make free content that the whole Internet can enjoy, and we love y'all for it. Patrons get access to neat perks, like the secret blooper reels we make every month. To get in on that, check out patreon.com/scishow. {♫Outro♫}